-Adding events and notification data model

1.9.2-head :001 >
User.first.inbox_notifications.first.notification.description
  User Load (0.2ms)  SELECT `users`.* FROM `users` LIMIT 1
  Inbox Load (0.1ms)  SELECT `inboxes`.* FROM `inboxes` WHERE
`inboxes`.`user_id` = 1 LIMIT 1
  Notification Load (0.1ms)  SELECT `notifications`.* FROM
`notifications` WHERE `notifications`.`id` = 1 LIMIT 1
 => "notification-1"